Topsy announced today that it has 460 billion pieces of data in its free search engine, including all tweets ever tweeted.

Since people began tweeting in 2006, Twitter has grown into an institution. It has become a rapid and efficient means for disseminating information; a genuine journalistic tool and reference source; and a place for the thoughts, feelings, advertisements, and self-promotions of every person, company, and organization with an Internet connection and a penchant for sharing. Though the number is not certain, it is likely that over 300 billion tweets have been published since 2006, and a social search engine called Topsy today announced that its archives, available to any Internet user to search for free, include every single one of those 300 billion tweets.

After adding videos, images, pins (from Pinterest), and other social data elements to its database of tweets, Topsy claims to have over 475 billion pieces of social content searchable on its website. Moreover, Topsy has its own proprietary means for sorting tweets. Explaining this to the New York Times, Vipul Ved Prakash, the founder of Topsy, said, "How do you make sense of 400 billion pieces of content? One, by ranking it. We do the ranking by looking at how much a particular piece of content is being cited by other people."

So, like Google (NASDAQ:GOOG), Topsy uses measures of influence and relevance to rank social content for its search engine.

Speaking of Google, the tech giant once had a deal with Twitter that allowed it to index all tweets. However, when that deal expired in 2011, it was not renewed and Google quickly became irrelevant when searching for up-to-date tweets. Topsy lets users search for content published within the past hour, since Twitter was launched, or within a specified date range.

Topsy is being covered quite broadly in the media today since the company announced its complete treasure trove of Twitter data, but it has been around since 2007. In fact, the social search company is one of the only surviving real-time search sites from the group that emerged between 2007 and 2010 -- a group that included startups such as Collecta, CrowdEye, OneRiot, Scoopler, and TweetMeme. Google and the other major search giants, namely Yahoo (NASDAQ:YHOO) and Bing (NASDAQ:MSFT), made survival very difficult for the real-time search engines. Now Topsy excels in this space, although it does have competitors, including DataSift and Gnip, neither of which offer free search; instead these two companies offer a paid product.

Topsy offers a paid product as well, and that's how it makes its money. For $12,000, clients like marketers, media companies, hedge funds, and political campaigns can have an annual subscription to Topsy's premium service, which allows them to narrow down search results by geography and other variables. Perhaps most importantly, the premium service can readily identify the tweets with most social influence on Twitter to help companies improve their social targeting.

Who then is perhaps Topsy's most important client? Twitter itself. In 2012, the Twitter Political Index, which tracked voter sentiment during the presidential election, used Topsy's search database. Earlier this year, the Twitter Oscars Index also employed Topsy. As Prakash said to the Times, "What we are doing is creating new products from the data. It becomes very complementary to the products that Twitter is providing." Because of this, Topsy may be a great candidate for a Twitter acquisition -- that is, unless the competition (like Google, Facebook (NASDAQ:FB), Microsoft, or Yahoo) beats it to the punch.